I do have a center console but no factory radio.Originally posted by John_Muha:
Don't have an easy way to chase it down. It's probably one of the dash lamps or a dash lamp socket. All the dash lamps have a gray wire. Need to unplug and remove the lamps to see which one it is. Do you have a center console with some lamps in it? Maybe something on that gray wire. If you are still using the factory radio, maybe that lamp or socket.